Settling-basin.



- E. S. COBB.

SETTLING BASIN.

APPLIOATION FILED 1111.3, 1913.

1,125,658. .Patented Jn. 19, 1915.

Hy. n

IIIIIHIInI 4f @x20/weg Vsolids froml water.

UNTTED sTATns PATENT ermee.

EDWARD s'. conn, or WHITTIER, CALIFORNIA..

snTTLING-nAsIN.

speeication of Letters Patent.

Patenten Jaa. ia, Tais.

Application led .Tanuary'8,-1913. Serial No. 739,997.

and silt and other solid matter which it is' highly desirable to remove before transmitting the water through-distribution systems for irrigation and' domestic'use'; as other- Wise the-sand and'silt will settle within the distribution system and eventually necessitate lits thorough cleaning.

Itis the prime object of -m'y invention Vto provide a simple and-leilici'ent 'device for obviating these fand other attendant diiiiculties byvseparating from the Water the sand and'silt and other solid matter before the water is passed into-a distributingsystem. Also, in cases 'where the water is raised from wells by :compressed air, itis importantto fully separate the air therefrom before sameis" allowed to enter `'dis- -or simultaneously with lthe separation of:

tributing pipes; 'and my apparatus is capable of sepa-rating such 'air either alone the solids. E

The essential fea-'turesfof myf/device aZre contained inafpan orba'sinit tlieperiplieial portions of which the water-fi's'injected' in such manner as to produce 1qiet 'litation' of the whole-body fwater, anafparuenianyef that portion of thewater 'adjacent vthe peripheryofth'e pan orbasin; tliefbasin liaving a central overflow 'outlet vfinto which 'the water ows topass-out of the device. In addition to th'eci'r'cular rt'atinof the'- water there is an 'inward 'movement dile "to 'the fact that the` supply is' at the periphery while the outlet is centrally located. -sthe water moves inwardly it graduallyv loses `:its rotational 'movement 'by' reasonl of 'friction with the bottomf-o'f thebsinand withtlr'e central outlet oveiiw wall. 'I'lietlover portions of -'the Water lois'eftllbii 'rotationalmevemetjt'e a greater*ekttthaneeestlie surface water, and the-,water whe-center loses most all of its rotational motion; hence, as will bemore particularly described, there is a slow upward and very slightly rotational movement of water at the center of the basin adjacent to the overflow wall of the outlet. This movement of the water, combined with the centrifugal action of the rotation and with the gravitational action, causes the settling'of most of the sand and silt and other solid particles tothe bottom at or near the outer boundary Wall. In this position the vdeposit is farthest from the outflow of clean water.

. I have illustrated a preferred form of my invention in the accompanying drawings, in which:

Figurel 1 is a plan, showing parts in section, of my settling basin. Fig. 2 is a vertical cross section of thesame. t

In the drawings I have shown a basin suitably constructed of reinforced concretel but any other material may be utilized. I.

have illustrated a basin having a 'flat bottom 10 with av vertical bounding wall 111, preferably circular yin form. I employ any desired number of tangential water inlets 12 which, in my concrete construction, are built into' the bounding wall 1l and are adapted to connect with suitable feed pipes. These inletsmay be ofany desi-red size and number; but are preferably vof such design as -to allow. the quiet inflow of a suitable amount of water corresponding to the capacity ofthe settlingbasin. The direction of the inlets may be any such as give rotation to the body ofwater in the basin; and I prefer to have inlets-l directed truly tangentia'lly. The bounding wall 11 has a waste overflownotch or depressionfl and a cleaning opening 14 for flushingout the accumulatedl deposits. The overiiow' 1S is for vthe purpose of preventing the water level. in the basin from rising abovea'A certain desi-redlevel. 4 I

Centrally situated within the basin, and

preferably'concentric with v'the outer bound- .ing wall, is an annular overflow wall 20 of llOO the general `configuration and designshown `y in' the drawings This overflow Wall in'- closes' a small overow basin 21 `from which Y thewate'r finds escapethrough outlet 22. A

suitable pip'e'or any other means 23 may be employed-for carrying oil' the clear water.

The upper @edge of the overflow Wall .is

slightly lower than the level of the waste digipresion-Ifand the water' in the basin normally extends to about the level indcated at 25. In operation, the water is let into the basin through the inlets 12, imparting to 5 the mass of water therein a slow quiet rof tation. In actual practice, the basin is of considerable diameter so that it may require some few minutes for the water to make a circuit of the outer edge. It will be seen that the rotational movement is gradually damped as the water proceeds inwardly,by friction with the bottom 10 and'with the overflow wall 20. The lower portions of the water lose more of theirk rotary motion than does the surface water; and consequently there is a tendency of the lower j water to move lnwardly at greater velocity than the upper water. 'Ilhis condition causes the actual upward movement of the water 2o near the overflow wall 20; and I have demonstrated that the larger part ofthe water passing over the overflow wall comes from below rather than from the surface. The u ward movement at the center is a measure o the total quantity of water acting and has only a `very slight rotational motion,V

depending upon the relative diameters of the two inclosing walls. The centrifugal action, being greatest at the outer periphery, induces deposit of heavier particles at this point. `As rotation speed reduces toward the center, gravitation will act on the lighter particles which will be deposited more generally over the whole bottom. The result is that in most cases the greatest deposit is made at points farthest from the outflow of the clear water.

The outowing water passes into the basin'.

21 and thence through the outlet 22. The 40 level in basin 21 may vary with the amount of water passing from the overflow wall; and this amountmay vary with variation of the water level in the settling basin. The limits between which thewater level in the settling basin may vary are fixed by' the height of the discharge overflow and of the waste overiownotch or depression 13. The waste overflow notch or depression 13 is j essential only as providing ay ixed point for the care of overow water in case more ishould be delivered to the settling basin at any time than is being drawn off through the regular discharge openings, as at l22.

Having described my invention,- Il claim: 1. A Icombined centrifugal and gravity settling basin, comprising a basin having a substantially circular bounding wall, a central outlet having a surroun mg overflow wal1 lower than said bounding wall, and means for injecting liquid substantially tangcntally into the cuter portions of 1the basin near the bounding wall, saidbasin being' unobstructed between said walls and bot# f tom. l 2. A combined centrifugal and gravity bounding wall, the length of the bounding wall and velocity of the linjection being suchl that the liquid requires some considerable time to complete the circuit, said basin being unobstructed between said walls and bottom. A

3. A combined centrifugal and gravity settling basin, comprising a basin having a substantiallycircular bounding wall, a central outlet having a surrounding overow wall lower than said bounding wall, and means for injecting liquid substantially tangentially into the outer portion of the basin near the bounding wall somewhat above the basin bottom, said basin being unobstructed between said walls and bottom.

4. A combined centrifugal and gravity settling basin, comprising an annular basin having an outer bounding wall and an inner overflow wall of less height and of considerably less diameter than that of the bounding wall, and tangential injection Y means for liquid at the bounding wall, the body of liquid near the bounding wall of the basin affected directly by the injection being only a small part of the whole body of liquid inthe basin, said basin being un- 'obstructed between said walls'and bottom.

5. A combined centrifugalV and gravity settling basin, comprising an annular basin having an outer bounding wall and an inner overiow wall of less height and of considerably less diameter than' that of the bounding wall, and tangential Vinjection tubes for liquid at the bounding-wall, the cross-sectional area of the tubes being small as com ared with the cross-sectional area of the asin, said basin being unobstructed between said walls and'bottom, Y

6. A combined l centrifugal and gravity settling basin, comprising a basin having a suitable bottom with a circular bounding wall, an outlet leading from the bottom center of the basin, a circular overflow wall surrounding the outlet andv of lesser height thanthe bounding wall, and liqud'injection v tubes discharging tangentially into the basin through the bounding wall somewhat above the basin bottom, said basin being unobstructed between said pwalls and bottom.

- 7 A combined centrifugal and gravity 'settling basin, comprising abasin having a 4center of the basin, a circular overow wall surrounding the outlet and of lesser height than the overflow of the bounding wall, and 130 liquid injection tubes discharging tangentially into the basin through the bounding wall somewhat above the basin bottom, said basin being unobstructed between said walls and bottom.

8. A combined centrifugal and gravity settling basin, comprising a basin having a suitable bottom and a vertical circular bounding wall of height considerably less than the basin diameter, an outlet pipe leading downwardly through the center of the basin bottom, the upper open end of the outlet pipe being above the bottom, a circular overliow wall concentrically surrounding the outlet pipe, said overow wall being of height less than that of the bounding wall, and liquid injecting tubes leading through the bounding wall somewhat above the basin bottom to inject liquid tangentially into the basin, said basin being unobstructed between said walls and bottom.

9. A combined centrifugal and gravity settling basin,.comprising a basin having a suitable bottom and a vertical, circular bounding wall of height considerably less than the basin diameter, said wall having an overflow notch on its upper edge and a cleaning opening at its bottom, an outlet pipe leading downwardly through the center of the basin bottom, the upper open end of the. outlet pipe being above the bottom, a circular overflow wall concentrically surrounding the outlet pipe, said overflow wall being of height less than that of the overflow of the bounding wall, and liquid injecting tubes leading through the bounding wall somewhat above the basin bottom to inject liquid tangentially into the basin, said basin being unobstructed between said walls and bottom.

In witness that l claim the foregoing I have hereunto subscribed my name this th day of December 1912.

EDWARD S. COBB.

Witnesses:

ELwooD H. BARKELEW, JAMES F. BARKELEW. 

